1. Field of the Invention
The present invention is an improved photoelectric sensor for an X-Y position input device which is made up of four photoelectric sensor areas on a photoelectric sensor chip in order to reduce the number of parts, to save production cost, and to reduce the defective rate.
2. Description of the Prior Art
The conventional optomechanical mouse uses the horizontal axis and vertical axis (referred to hereinafter as the X-axis and the Y-axis) of a photoelectric sensor X-Y position device to control the mouse cursor to a relative position on a monitor. However, the photoelectric sensor for the X-axis and Y-axis is made up of two phototransistors, two LEDs; one slotted disc and one shaft. The emitting sides of the LEDs face the receiving sides of the phototransistors (the respective pairs of components being hereinafter referred to as photoelectric sets), with the slots and slotted wall of the slotted disc set up in between the two photoelectric sets. When the shaft drives the slotted disc to rotate, it causes illumination or shade from the light of the LED, and the intermittent light signal which is received by the phototransistors is used to produce a series of pulse signals to control the mouse control circuit. Generally, the slotted disc uses the two identical photoelectric sets to generate a set of signals having a phase difference which depends on whether the slotted disc rotates forward or backward. In general, if the X-axis slotted disc rotates forward, the cursor of the monitor moves to the right. In contrast, if the slotted disc rotates backward, the cursor moves to the left. If the Y-axis slotted disc rotates forward, the cursor of the monitor moves up, In contrast, if the slotted disc rotates backward, the cursor moves down. Thus, a ball member drives the X-axis and Y-axis shafts in order to achieve the mouse's objective of controlling the cursor on the monitor.